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Mechanical Engineering
Mechanical Engineering is a branch of engineering that encompasses the generation and application of heat and mechanical power and the design, production, and use of machines and tools. Mechanical engineering involves application of the principles of dynamics, control, thermodynamics and heat transfer, fluid mechanics, strength of materials, materials science, electronics, and mathematics.
10,989 Questions
What happens to strain as stress increases?
it also increases in the same proportion as stress. Stress equals strain times a constant, where the constant is Young's modulus. This is Hooke's Law
Where will you find the maximum shear stress in a beam?
The maximum stress occurs where shear load is maximum and maximum stress is at the center of the beam cross section if loaded in shear due to bending. It drops to zero at the top and bottom surfaces. The average stress is load divided by area ; maximum stress is dependent on shape of cross section and is 1.5 times load divided by area at the cross section center for rectangular cross section.
For shear due to twist, max shear stress in the outer surface.
How long will 100000 gallons of diesel fuel power a 3 MW generator?
The standard specific fuel consumption for a heat engine is 0.5 lb per HP per hour.
A 3 MW generator is 4000 HP but allowing for conversion efficiency the engine would probably have to provide 5000 HP, so using the above specific fuel consumption the rate of fuel use would be 2500 lb fuel per hour.
With a specific density of 0.8 2500 lb of fuel would have a volume of 310 gallons. This generator uses 310 gallons per hour, therefore 100,000 gallons would last 100,000/310 hours or 322 hours, just under 2 weeks.
Who establishes mandatory replacement times for critical components of turbine engines?
Usually the manufacturer
What types of material would have a yield point?
all materials that are ductile, including almost all metals and plastics. Those materials that are brittle, like glass and ceramics, do not have defined yield points; they simply break
What the difference between process piping and power piping?
What the difference between process piping and power piping?
A weld log is a Quality Managment tool that acts as a database used to keep an ongoing record of welds made during construction fabrication type projects. The Weld log is used to record Important information recorded as "weld number" Welders Stencils", "Weld Procedure", "Weld Type" Material Type" "Project#" and any other important information to ensure the traceability and Quality Assurance of each welded junction during fabrication or repair activities.
The best example can be found here:
http://sites.google.com/site/masterweldtracker/
Duplex Stainless Steel pipes are using when the corrosion allowance is exceed the limit to do Stainless Steel pipes. The maximum corrosion allowance allowed in a Design life (7000 cycle / 20 years) is 3 or 6 mm. This having a high yield strength than the S.S pipes
Why 0.2 percent is used to find offset yield strength?
Due to the difficulty of locating the precise point at which the slope of the modulus line begins to change, indicating the onset of plastic deformation and the yield point. By placing a line parallel to the modulus line it is much easier to see the precise point at which they intersect. The selection of .2% is just a convenient distance to provide a good visible intersection and assure a very reasonable degree of accuracy.
refers to the threads per inch for example screw cutting
What does porosity in a weld means?
Porosity in welding is a result of dissolved gases or gases released during the welding process, being trapped in the metal when there is insufficient time to escape prior to solidification. If in the shape of rounded holes, the gas is called spherical porosity or just porosity. However, if elongated the terminology is wormholes or piping. Causes of porosity are;
- excessively long or short arc length
- welding current too high
- insufficient or moist shielding gas
- travel speed to fast
- base metal covered with oil, grease, moisture etc.
- wet, unclean or damaged electrodes.
Multiply the number of square inches times the pounds per square inch. In this case, 5 x 50- or 250 pounds of force.
you need to find out the necessary force and supports for the design before building it.
Working principal type description operation of shaping machine?
there are two stroke include in this forward stroke &return stroke
during the forward stroke machine works means it removes the material from workpiece & during the return stroke machine remains idle
What is the function of absorber in vapour absorption refrigeration system?
in orde to reduce the pressure........cming from the evaporator
What is intercritical annealing?
Intercritical annealing is where the metal is heated to between its lower and upper critical temperature point to allow partial transformation of the matrix into austenite followed by slow cooling or holding below the lower critical temperature point.
What is bourdon tube pressure gauge?
An elastic transducer, that is bourdon tube which is fixed and open at one end to receive the pressure which is to be measured. The other end of the bourdon tube is free and closed.
The cross-section of the bourdon tube is eliptical. The bourdon tube is in a bent form to look like a circular arc. To the free end of the bourdon tube is attached an adjustable link, which is inturn connected to a sector and pinion as shown in diagram. To the shaft of the pinion is connected a pointer which sweeps over a pressure calibrated scale.
What is the unit for yield strength?
kg/cm²
Yield strength is same as yield stress and are in dimensions of [force]/[area]
In US, typical unit would be PSI ( lb/in^2) or KSI (kilo lb/in^2)
In SI, typical unit would be Pa ( N/m^2) or MPa ( million N / m^2)
